Fiber optic cables are well known for connecting optical devices and systems. Some cables carry multiple fibers and have one or more connectors. “Pre-connectorized” cables have their connectors attached during manufacture, while others are terminated and have connectors attached upon installation. Cables known as patch cables, jumper cables, and fan-out cable assemblies are often relatively short and have one or more connectors at each end. In use, each connector will be placed within a port or socket located in a piece of equipment, patch panel, another connector, adaptor, etc.
As fiber optic equipment and networks become more common and more complex, the identification of proper cables, ports, and connectors for setting up and maintaining the systems accordingly becomes more complex. Therefore, indicia such as labels, hang tags, marking, coloration, and striping have been used to help identify specific fibers, cables, and/or connectors. While such indicia have been helpful in providing information to the technician setting up or servicing a system, further improvement could be achieved.
RFID systems can therefore be applied to fiber optic systems to provide information regarding fibers, components, connectors, and ports. For example, RFID elements (comprising an antenna and an RFID integrated circuit chip, functioning as a transponder) could be attached to connectors and ports for use in identification. The RFID chip stores information for RF transmission. Typically, these RFID elements are proposed to be passive, rather than powered, so they communicate the stored information responsive to interrogation by an RF signal received by the RFID element antenna. An RFID reader comprising a transceiver that sends an RF signal to the RFID elements and reads the responsive RF signals communicated by the RFID elements could then interrogate the RFID elements to determine stored information about the cable, component, connector, and/or port. In some fiber optic connector systems, an RFID transceiver antenna is located near the port for detecting an RFID element attached to the inserted connector, and the transceiver antenna further is connected to the remainder of the transceiver via wiring.
It is typically not feasible to employ powered (i.e., Semi passive or Active) RFID elements in complicated electro-optical systems because of the cost and complexity of incorporating such powered systems. Essentially, separate power sources and connections must be provided for the various RFID elements. Where a system is built using individual, modular, and/or reconfigurable components, use of powered RFID systems is not advantaged.
The various systems above generally rely upon a certain degree of proximity for operation. That is, the reader in the system would identify nearby RFID elements, or would identify pairs of elements close together (for example, on a connector and on a port holding the connector), all within the read range of the reader. The read range could be designed to be small, for example for rows of readers mounted on adjacent ports for reading only an inserted connector's RFID signal. Alternatively, the read range could be much larger, for example for handheld or room-size readers for reading multiple signals from one or more pieces of equipment.
However, such RFID systems have certain drawbacks. For example, depending for operation on the relative proximity to a targeted item can lead to either difficult or inaccurate results, as signals may be received and transmitted by unintended RFID elements on items nearby to the targeted item. Accordingly, the read range of a given RFID reader, whether incorporated into the port housing or separate, can be a limiting factor. Further, if a connector were only partially inserted into a port so as not to make a functional connection with the optical fiber(s), the RFID antennas in the connector and port or reader might inaccurately indicate the connection were made due to the proximity between the connector and port.
Moreover, when dealing with an entire panel of connectorized cables and ports, it may not be practical or even possible to rely upon proximity, either connector-to-port or reader-to-RFID element, as a method of querying a targeted RFID element. In fact, the RFID elements across the entire panel could respond to an RFID reader in certain situations, thereby providing no useful information as to identification of individual connectors or ports of interest.
Also, if identification of a certain RFID element is desired, upon query by a reader certain identifying indicia must be provided to the operator so as to find the RFID element. If such information is not pre-programmed into the RFID element chip or reader database at some point, it can be difficult or impossible to make such identification, even if the reader and RFID element are in full communication with each other.
In such situation, a technician may have to separate a connector from the port and panel to obtain information from the RFID element of the connector or port, thereby breaking the fiber optic connection in the process. Such action adds a step to the process of identification in terms of unplugging or at least re-orienting objects in a certain way to avoid “false” readings from the panel due to proximity issues. Also, it may be necessary to disconnect the optical fiber connectors, possibly one after another, until a targeted optical fiber is found. Such serial disconnection can be even more undesirable when equipment is operating and disconnections cause problems for the users of the systems. In such cases, the whole system may have to be shut down just to allow for the identification of a single cable, even if sophisticated RFID equipment is in place. The process becomes more complex when extended to entire networks including multiple equipment housings, cables, etc., perhaps spread throughout a building.
Therefore, further improvements in RFID technology and its application to fiber optic systems to allow for simple, reliable, and/or unobtrusive identification of one or more targeted items and/or mapping of networks would be welcome.